Diageo has delivered a modest 0.3% share price gain over the past year, yet a much weaker multi year record raises a sharper question for investors about whether the current valuation is still supported by the cash the business can generate. Recent headlines around its Scotch imports in India add another layer to that question because they touch directly on trade flows, taxes and ultimately cash flows. Over 5 years the stock has fallen 43.4%. This puts the spotlight firmly on whether the…